THE CONSERVATION OF AFRICAN PLAINS GAME 345 



known. Whatever it may be, the soils and vegetation here are being heavily 

 punished by indiscriminate burning, and as a result the vegetation almost 

 always shows signs of being a fire-climax (cf Shantz & Marbut, 1923), lower 

 in nutrient status and in water status than it should be. 



The possibility of maintaining the plains game thus depends on sacrificing 

 to them a useful proportion of the dry-season grazing, a share of the wet- 

 season grazing, and probably also on maintaining the fertility of the inter- 

 vening 'bush'. 



It will be seen that the proposals necessary to preserve the migration cycle 

 of the plains game here involve an area of somethmg like 5,175 square km 

 (2,000 square miles). Some of the ecological problems involved may now be 

 considered. 



RIVAL METHODS OF PROTEIN PRODUCTION 



There is much evidence that protein production is often a desirable form of 

 land use in these arid cHmates. In East Africa generally, the soils show very 

 rapid nitrogen turnover, organic matter decays very quickly and the high 

 calcium status of the rooting levels and vegetation in the plains is a feature 

 normally associated with a protein-rich vegetation as it is here. The marginal 

 level of the rainfall in the Serengeti and its uncertainty, however, preclude 

 the regular use of cereal crops for protein production, as on an average the 

 rainfall is hkely to be insufficient in one year out of four or five (Glover & 

 Robinson, 1955). Animal cropping is thus considered to be the present 

 alternative, and it is evidently also the natural ecological form of land use. 

 We can in the Serengeti contrast this natural form of land use in what we 

 can call the plains-game eco-system with the human pastoral form evolved 

 and followed by the Masai. 



DIFFICULTIES OF THE HABITAT 



In addition to the seasonal scarcity of water, an obstacle to the use of domestic 

 stock and especially to human occupation in the Serengeti is the character 

 of many of the sources of water. As the dry season develops, the surface waters 

 accessible to animals become extremely saline and in the foothills of the 

 Crater Highlands and on the volcanic dust areas, the waters may contain 

 quantities of fluorine which would be highly deleterious to human beings 

 and harmful to most forms of domestic stock. A concentration of fluoride 

 of the order of three parts per million of water is accepted as the desirable 

 Hmit for human beings and 15 p.p. mill, is usually regarded as the limit for 

 cattle, while 18-25 pp. mill, are known to give harmful effects in Tanganyika. 

 Amounts of this order or above are frequent in the Serengeti surface waters 

 (Pearsall, 1957). 



